| Message ID | 20220922003214.276736-4-gshan@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: arm64: Enable ring-based dirty memory tracking | expand |
On Thu, 22 Sep 2022 01:32:11 +0100, Gavin Shan <gshan@redhat.com> wrote: > > This enables the ring-based dirty memory tracking on ARM64. The > feature is configured by CONFIG_HAVE_KVM_DIRTY_RING, detected and > enabled by KVM_CAP_DIRTY_LOG_RING. A ring buffer is created on every > VCPU when the feature is enabled. Each entry in the ring buffer is > described by 'struct kvm_dirty_gfn'. > > A ring buffer entry is pushed when a page becomes dirty on host, > and pulled by userspace after the ring buffer is mapped at physical > page offset KVM_DIRTY_LOG_PAGE_OFFSET. The specific VCPU is enforced > to exit if its ring buffer becomes softly full. Besides, the ring > buffer can be reset by ioctl command KVM_RESET_DIRTY_RINGS to release > those pulled ring buffer entries. I think you can cut this message short. This description was useful when the feature was initially merged, but this is only a "plumb the damn thing" patch. > > Signed-off-by: Gavin Shan <gshan@redhat.com> > --- > Documentation/virt/kvm/api.rst | 2 +- > arch/arm64/include/uapi/asm/kvm.h | 1 + > arch/arm64/kvm/Kconfig | 1 + > arch/arm64/kvm/arm.c | 8 ++++++++ > 4 files changed, 11 insertions(+), 1 deletion(-) > > diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst > index abd7c32126ce..19fa1ac017ed 100644 > --- a/Documentation/virt/kvm/api.rst > +++ b/Documentation/virt/kvm/api.rst > @@ -8022,7 +8022,7 @@ regardless of what has actually been exposed through the CPUID leaf. > 8.29 KVM_CAP_DIRTY_LOG_RING > --------------------------- > > -:Architectures: x86 > +:Architectures: x86, arm64 > :Parameters: args[0] - size of the dirty log ring > > KVM is capable of tracking dirty memory using ring buffers that are > diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h > index 316917b98707..a7a857f1784d 100644 > --- a/arch/arm64/include/uapi/asm/kvm.h > +++ b/arch/arm64/include/uapi/asm/kvm.h > @@ -43,6 +43,7 @@ > #define __KVM_HAVE_VCPU_EVENTS > > #define KVM_COALESCED_MMIO_PAGE_OFFSET 1 > +#define KVM_DIRTY_LOG_PAGE_OFFSET 64 > > #define KVM_REG_SIZE(id) \ > (1U << (((id) & KVM_REG_SIZE_MASK) >> KVM_REG_SIZE_SHIFT)) > diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig > index 815cc118c675..0309b2d0f2da 100644 > --- a/arch/arm64/kvm/Kconfig > +++ b/arch/arm64/kvm/Kconfig > @@ -32,6 +32,7 @@ menuconfig KVM > select KVM_VFIO > select HAVE_KVM_EVENTFD > select HAVE_KVM_IRQFD > + select HAVE_KVM_DIRTY_RING > select HAVE_KVM_MSI > select HAVE_KVM_IRQCHIP > select HAVE_KVM_IRQ_ROUTING > diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c > index 2ff0ef62abad..76816f8e082b 100644 > --- a/arch/arm64/kvm/arm.c > +++ b/arch/arm64/kvm/arm.c > @@ -747,6 +747,14 @@ static int check_vcpu_requests(struct kvm_vcpu *vcpu) > > if (kvm_check_request(KVM_REQ_SUSPEND, vcpu)) > return kvm_vcpu_suspend(vcpu); > + > + if (kvm_check_request(KVM_REQ_RING_SOFT_FULL, vcpu) && > + kvm_dirty_ring_soft_full(&vcpu->dirty_ring)) { > + kvm_make_request(KVM_REQ_RING_SOFT_FULL, vcpu); > + vcpu->run->exit_reason = KVM_EXIT_DIRTY_RING_FULL; > + trace_kvm_dirty_ring_exit(vcpu); > + return 0; > + } This is *very* similar to the x86 code. Could we move it to common code? Something like the diff below, to be for most of it squashed into patch #1. Thanks, M. diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 76816f8e082b..93a16cdbe163 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -748,13 +748,8 @@ static int check_vcpu_requests(struct kvm_vcpu *vcpu) if (kvm_check_request(KVM_REQ_SUSPEND, vcpu)) return kvm_vcpu_suspend(vcpu); - if (kvm_check_request(KVM_REQ_RING_SOFT_FULL, vcpu) && - kvm_dirty_ring_soft_full(&vcpu->dirty_ring)) { - kvm_make_request(KVM_REQ_RING_SOFT_FULL, vcpu); - vcpu->run->exit_reason = KVM_EXIT_DIRTY_RING_FULL; - trace_kvm_dirty_ring_exit(vcpu); + if (kvm_dirty_ring_check_request(vcpu)) return 0; - } } return 1; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index eb7d0d7654bb..48f2519b1db7 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -10249,11 +10249,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) if (kvm_request_pending(vcpu)) { /* Forbid vmenter if vcpu dirty ring is soft-full */ - if (kvm_check_request(KVM_REQ_RING_SOFT_FULL, vcpu) && - kvm_dirty_ring_soft_full(&vcpu->dirty_ring)) { - kvm_make_request(KVM_REQ_RING_SOFT_FULL, vcpu); - vcpu->run->exit_reason = KVM_EXIT_DIRTY_RING_FULL; - trace_kvm_dirty_ring_exit(vcpu); + if (kvm_dirty_ring_check_request(vcpu)) { r = 0; goto out; } diff --git a/include/linux/kvm_dirty_ring.h b/include/linux/kvm_dirty_ring.h index 8c6755981c9b..6e484220adc0 100644 --- a/include/linux/kvm_dirty_ring.h +++ b/include/linux/kvm_dirty_ring.h @@ -64,11 +64,6 @@ static inline void kvm_dirty_ring_free(struct kvm_dirty_ring *ring) { } -static inline bool kvm_dirty_ring_soft_full(struct kvm_dirty_ring *ring) -{ - return true; -} - #else /* CONFIG_HAVE_KVM_DIRTY_RING */ int kvm_cpu_dirty_log_size(void); @@ -91,7 +86,7 @@ void kvm_dirty_ring_push(struct kvm_dirty_ring *ring, u32 slot, u64 offset); struct page *kvm_dirty_ring_get_page(struct kvm_dirty_ring *ring, u32 offset); void kvm_dirty_ring_free(struct kvm_dirty_ring *ring); -bool kvm_dirty_ring_soft_full(struct kvm_dirty_ring *ring); +bool kvm_dirty_ring_check_request(struct kvm_vcpu *vcpu); #endif /* CONFIG_HAVE_KVM_DIRTY_RING */ diff --git a/virt/kvm/dirty_ring.c b/virt/kvm/dirty_ring.c index 69c8c90d489d..436d7cded5bf 100644 --- a/virt/kvm/dirty_ring.c +++ b/virt/kvm/dirty_ring.c @@ -26,7 +26,7 @@ static u32 kvm_dirty_ring_used(struct kvm_dirty_ring *ring) return READ_ONCE(ring->dirty_index) - READ_ONCE(ring->reset_index); } -bool kvm_dirty_ring_soft_full(struct kvm_dirty_ring *ring) +static bool kvm_dirty_ring_soft_full(struct kvm_dirty_ring *ring) { return kvm_dirty_ring_used(ring) >= ring->soft_limit; } @@ -182,3 +182,16 @@ void kvm_dirty_ring_free(struct kvm_dirty_ring *ring) vfree(ring->dirty_gfns); ring->dirty_gfns = NULL; } + +bool kvm_dirty_ring_check_request(struct kvm_vcpu *vcpu) +{ + if (kvm_check_request(KVM_REQ_RING_SOFT_FULL, vcpu) && + kvm_dirty_ring_soft_full(&vcpu->dirty_ring)) { + kvm_make_request(KVM_REQ_RING_SOFT_FULL, vcpu); + vcpu->run->exit_reason = KVM_EXIT_DIRTY_RING_FULL; + trace_kvm_dirty_ring_exit(vcpu); + return true; + } + + return false; +}
Hi Marc, On 9/25/22 6:27 AM, Marc Zyngier wrote: > On Thu, 22 Sep 2022 01:32:11 +0100, > Gavin Shan <gshan@redhat.com> wrote: >> >> This enables the ring-based dirty memory tracking on ARM64. The >> feature is configured by CONFIG_HAVE_KVM_DIRTY_RING, detected and >> enabled by KVM_CAP_DIRTY_LOG_RING. A ring buffer is created on every >> VCPU when the feature is enabled. Each entry in the ring buffer is >> described by 'struct kvm_dirty_gfn'. >> >> A ring buffer entry is pushed when a page becomes dirty on host, >> and pulled by userspace after the ring buffer is mapped at physical >> page offset KVM_DIRTY_LOG_PAGE_OFFSET. The specific VCPU is enforced >> to exit if its ring buffer becomes softly full. Besides, the ring >> buffer can be reset by ioctl command KVM_RESET_DIRTY_RINGS to release >> those pulled ring buffer entries. > > I think you can cut this message short. This description was useful > when the feature was initially merged, but this is only a "plumb the > damn thing" patch. > Agreed. I will modify the changelog in v4 accordingly, thanks. >> >> Signed-off-by: Gavin Shan <gshan@redhat.com> >> --- >> Documentation/virt/kvm/api.rst | 2 +- >> arch/arm64/include/uapi/asm/kvm.h | 1 + >> arch/arm64/kvm/Kconfig | 1 + >> arch/arm64/kvm/arm.c | 8 ++++++++ >> 4 files changed, 11 insertions(+), 1 deletion(-) >> >> diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst >> index abd7c32126ce..19fa1ac017ed 100644 >> --- a/Documentation/virt/kvm/api.rst >> +++ b/Documentation/virt/kvm/api.rst >> @@ -8022,7 +8022,7 @@ regardless of what has actually been exposed through the CPUID leaf. >> 8.29 KVM_CAP_DIRTY_LOG_RING >> --------------------------- >> >> -:Architectures: x86 >> +:Architectures: x86, arm64 >> :Parameters: args[0] - size of the dirty log ring >> >> KVM is capable of tracking dirty memory using ring buffers that are >> diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h >> index 316917b98707..a7a857f1784d 100644 >> --- a/arch/arm64/include/uapi/asm/kvm.h >> +++ b/arch/arm64/include/uapi/asm/kvm.h >> @@ -43,6 +43,7 @@ >> #define __KVM_HAVE_VCPU_EVENTS >> >> #define KVM_COALESCED_MMIO_PAGE_OFFSET 1 >> +#define KVM_DIRTY_LOG_PAGE_OFFSET 64 >> >> #define KVM_REG_SIZE(id) \ >> (1U << (((id) & KVM_REG_SIZE_MASK) >> KVM_REG_SIZE_SHIFT)) >> diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig >> index 815cc118c675..0309b2d0f2da 100644 >> --- a/arch/arm64/kvm/Kconfig >> +++ b/arch/arm64/kvm/Kconfig >> @@ -32,6 +32,7 @@ menuconfig KVM >> select KVM_VFIO >> select HAVE_KVM_EVENTFD >> select HAVE_KVM_IRQFD >> + select HAVE_KVM_DIRTY_RING >> select HAVE_KVM_MSI >> select HAVE_KVM_IRQCHIP >> select HAVE_KVM_IRQ_ROUTING >> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c >> index 2ff0ef62abad..76816f8e082b 100644 >> --- a/arch/arm64/kvm/arm.c >> +++ b/arch/arm64/kvm/arm.c >> @@ -747,6 +747,14 @@ static int check_vcpu_requests(struct kvm_vcpu *vcpu) >> >> if (kvm_check_request(KVM_REQ_SUSPEND, vcpu)) >> return kvm_vcpu_suspend(vcpu); >> + >> + if (kvm_check_request(KVM_REQ_RING_SOFT_FULL, vcpu) && >> + kvm_dirty_ring_soft_full(&vcpu->dirty_ring)) { >> + kvm_make_request(KVM_REQ_RING_SOFT_FULL, vcpu); >> + vcpu->run->exit_reason = KVM_EXIT_DIRTY_RING_FULL; >> + trace_kvm_dirty_ring_exit(vcpu); >> + return 0; >> + } > > This is *very* similar to the x86 code. Could we move it to common > code? Something like the diff below, to be for most of it squashed > into patch #1. > Sure, the additional changes make sense to me. I will fold them to PATCH[v4 1/6]. Thanks, Gavin > > diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c > index 76816f8e082b..93a16cdbe163 100644 > --- a/arch/arm64/kvm/arm.c > +++ b/arch/arm64/kvm/arm.c > @@ -748,13 +748,8 @@ static int check_vcpu_requests(struct kvm_vcpu *vcpu) > if (kvm_check_request(KVM_REQ_SUSPEND, vcpu)) > return kvm_vcpu_suspend(vcpu); > > - if (kvm_check_request(KVM_REQ_RING_SOFT_FULL, vcpu) && > - kvm_dirty_ring_soft_full(&vcpu->dirty_ring)) { > - kvm_make_request(KVM_REQ_RING_SOFT_FULL, vcpu); > - vcpu->run->exit_reason = KVM_EXIT_DIRTY_RING_FULL; > - trace_kvm_dirty_ring_exit(vcpu); > + if (kvm_dirty_ring_check_request(vcpu)) > return 0; > - } > } > > return 1; > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index eb7d0d7654bb..48f2519b1db7 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -10249,11 +10249,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) > > if (kvm_request_pending(vcpu)) { > /* Forbid vmenter if vcpu dirty ring is soft-full */ > - if (kvm_check_request(KVM_REQ_RING_SOFT_FULL, vcpu) && > - kvm_dirty_ring_soft_full(&vcpu->dirty_ring)) { > - kvm_make_request(KVM_REQ_RING_SOFT_FULL, vcpu); > - vcpu->run->exit_reason = KVM_EXIT_DIRTY_RING_FULL; > - trace_kvm_dirty_ring_exit(vcpu); > + if (kvm_dirty_ring_check_request(vcpu)) { > r = 0; > goto out; > } > diff --git a/include/linux/kvm_dirty_ring.h b/include/linux/kvm_dirty_ring.h > index 8c6755981c9b..6e484220adc0 100644 > --- a/include/linux/kvm_dirty_ring.h > +++ b/include/linux/kvm_dirty_ring.h > @@ -64,11 +64,6 @@ static inline void kvm_dirty_ring_free(struct kvm_dirty_ring *ring) > { > } > > -static inline bool kvm_dirty_ring_soft_full(struct kvm_dirty_ring *ring) > -{ > - return true; > -} > - > #else /* CONFIG_HAVE_KVM_DIRTY_RING */ > > int kvm_cpu_dirty_log_size(void); > @@ -91,7 +86,7 @@ void kvm_dirty_ring_push(struct kvm_dirty_ring *ring, u32 slot, u64 offset); > struct page *kvm_dirty_ring_get_page(struct kvm_dirty_ring *ring, u32 offset); > > void kvm_dirty_ring_free(struct kvm_dirty_ring *ring); > -bool kvm_dirty_ring_soft_full(struct kvm_dirty_ring *ring); > +bool kvm_dirty_ring_check_request(struct kvm_vcpu *vcpu); > > #endif /* CONFIG_HAVE_KVM_DIRTY_RING */ > > diff --git a/virt/kvm/dirty_ring.c b/virt/kvm/dirty_ring.c > index 69c8c90d489d..436d7cded5bf 100644 > --- a/virt/kvm/dirty_ring.c > +++ b/virt/kvm/dirty_ring.c > @@ -26,7 +26,7 @@ static u32 kvm_dirty_ring_used(struct kvm_dirty_ring *ring) > return READ_ONCE(ring->dirty_index) - READ_ONCE(ring->reset_index); > } > > -bool kvm_dirty_ring_soft_full(struct kvm_dirty_ring *ring) > +static bool kvm_dirty_ring_soft_full(struct kvm_dirty_ring *ring) > { > return kvm_dirty_ring_used(ring) >= ring->soft_limit; > } > @@ -182,3 +182,16 @@ void kvm_dirty_ring_free(struct kvm_dirty_ring *ring) > vfree(ring->dirty_gfns); > ring->dirty_gfns = NULL; > } > + > +bool kvm_dirty_ring_check_request(struct kvm_vcpu *vcpu) > +{ > + if (kvm_check_request(KVM_REQ_RING_SOFT_FULL, vcpu) && > + kvm_dirty_ring_soft_full(&vcpu->dirty_ring)) { > + kvm_make_request(KVM_REQ_RING_SOFT_FULL, vcpu); > + vcpu->run->exit_reason = KVM_EXIT_DIRTY_RING_FULL; > + trace_kvm_dirty_ring_exit(vcpu); > + return true; > + } > + > + return false; > +} >
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index abd7c32126ce..19fa1ac017ed 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -8022,7 +8022,7 @@ regardless of what has actually been exposed through the CPUID leaf. 8.29 KVM_CAP_DIRTY_LOG_RING --------------------------- -:Architectures: x86 +:Architectures: x86, arm64 :Parameters: args[0] - size of the dirty log ring KVM is capable of tracking dirty memory using ring buffers that are diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h index 316917b98707..a7a857f1784d 100644 --- a/arch/arm64/include/uapi/asm/kvm.h +++ b/arch/arm64/include/uapi/asm/kvm.h @@ -43,6 +43,7 @@ #define __KVM_HAVE_VCPU_EVENTS #define KVM_COALESCED_MMIO_PAGE_OFFSET 1 +#define KVM_DIRTY_LOG_PAGE_OFFSET 64 #define KVM_REG_SIZE(id) \ (1U << (((id) & KVM_REG_SIZE_MASK) >> KVM_REG_SIZE_SHIFT)) diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig index 815cc118c675..0309b2d0f2da 100644 --- a/arch/arm64/kvm/Kconfig +++ b/arch/arm64/kvm/Kconfig @@ -32,6 +32,7 @@ menuconfig KVM select KVM_VFIO select HAVE_KVM_EVENTFD select HAVE_KVM_IRQFD + select HAVE_KVM_DIRTY_RING select HAVE_KVM_MSI select HAVE_KVM_IRQCHIP select HAVE_KVM_IRQ_ROUTING diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 2ff0ef62abad..76816f8e082b 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -747,6 +747,14 @@ static int check_vcpu_requests(struct kvm_vcpu *vcpu) if (kvm_check_request(KVM_REQ_SUSPEND, vcpu)) return kvm_vcpu_suspend(vcpu); + + if (kvm_check_request(KVM_REQ_RING_SOFT_FULL, vcpu) && + kvm_dirty_ring_soft_full(&vcpu->dirty_ring)) { + kvm_make_request(KVM_REQ_RING_SOFT_FULL, vcpu); + vcpu->run->exit_reason = KVM_EXIT_DIRTY_RING_FULL; + trace_kvm_dirty_ring_exit(vcpu); + return 0; + } } return 1;
This enables the ring-based dirty memory tracking on ARM64. The feature is configured by CONFIG_HAVE_KVM_DIRTY_RING, detected and enabled by KVM_CAP_DIRTY_LOG_RING. A ring buffer is created on every VCPU when the feature is enabled. Each entry in the ring buffer is described by 'struct kvm_dirty_gfn'. A ring buffer entry is pushed when a page becomes dirty on host, and pulled by userspace after the ring buffer is mapped at physical page offset KVM_DIRTY_LOG_PAGE_OFFSET. The specific VCPU is enforced to exit if its ring buffer becomes softly full. Besides, the ring buffer can be reset by ioctl command KVM_RESET_DIRTY_RINGS to release those pulled ring buffer entries. Signed-off-by: Gavin Shan <gshan@redhat.com> --- Documentation/virt/kvm/api.rst | 2 +- arch/arm64/include/uapi/asm/kvm.h | 1 + arch/arm64/kvm/Kconfig | 1 + arch/arm64/kvm/arm.c | 8 ++++++++ 4 files changed, 11 insertions(+), 1 deletion(-)